Modern irrigation systems employ subterranean pumps connected by lengths of flexible tubing in irrigation trenches and to a water supply. Although various types of flexible tubing are known, the most commonly used tubing today is a polyolefin, such as polyethylene, usually referred to by those in the industry as “poly.” The underground pump is typically electrically driven, so a power wire, cord or cable is typically attached to the flexible tubing, as by taping the cable to the tubing.
In systems which have underground pumps for pumping water through long flexible plastic tubing of the type which has been described (hereafter “well flexible tubing”), tubing installation and removal has tended to be a difficult operation since these procedures are labor intensive and time consuming. It is not unusual for a crew of five or six people to be deployed to pull poly from the ground to replace or maintain a pump.
There are various reasons why it is necessary to pull the well tubing from the irrigation trenches. On occasion, it is necessary to access the underground pump, either for servicing or replacement, or because the pump must be relocated at a different elevation in the ground. In the past, when removal of the submersible pump was necessary, often the pump had to be physically removed from the ground as by raising the pump by the flexible water pipe or tubing. Since irrigation trenches can be hundreds of feet long, this results in hundreds of feet of length of the flexible water pipe and associated electrical wiring which must be accommodated. Removal of underground pumps, as well as the removal of other types of irrigation and servicing devices, such as coiled tubing, has previously been accomplished by a variety of methods. In small plots, where the weight of the pump and the length of the flexible water pipe tubing is relatively small, physical manual hoisting of the pump and pipe has sometimes been used.
Various mechanical devices have been developed over the years for removing other types of well devices. For example, U.S. Pat. No. 6,502,641 to Carriere, et al. shows a coiled tubing rig which includes a frame, a tiltable mast and an injector reel. The mast can be tilted to a position that aligns the coiled tubing with the BOP. However, this device is not used as a device for pulling a submersible pump from a well.
U.S. Pat. No. 5,848,641 shows a well pump puller. Modem water wells are drilled into the ground with the well bore either being uncased, or being protected by a casing which is sunk into the well. Typically, a submersible pump is then run down the well bore on flexible tubing and submerged Although this reference shows a cylindrical drum and a companion guide, it does not appear that the cylindrical drum pivots from the horizontal to a vertical position.
U.S. Pat. No. 3,116,781 shows a well workover apparatus 20 including a cylindrical drum 12 and a yoke mechanism 18.
U.S. Pat. No. 3,991,978 shows a submersible pump boom which can be used for pulling or replacing a submersible pump.
U.S. Pat. No. 4,986,351 shows a device used for pump removal which includes a collar which is secured to the upper end of a well casing.
U.S. Pat. No. 4,523,645 shows an apparatus for removing reeved material from a wellbore such as a cable, electrical line or fluid conductor.
U.S. Pat. No. 4,296,916 shows another type of device for pulling submersible pumps from a well bore.
U.S. Pat. No. 4,673,035 is another apparatus which deals with a coil tubing operation. This reference does appear to show a cylindrical drum (25 in FIG. 1) which may be elevated to allow the operation of the apparatus with elevated well heads.
U.S. Pat. No. 5,996,971 shows another type of well pipe hoist which is secured to the well casing at the top of the well.
While the above references, and others, show a variety of devices which have been used in the past for raising and lowering flexible tubing from a well bore, a need continues to exist for an improved submersible pump puller which is simple in design, economical to manufacture and requires a small crew of human operators than prior designs and methods.
A need also exists for such a device which can be portably mounted for transport from one well location to another.
A need also exists for such an apparatus which evenly centers the vertical axis of the flexible tubing being fed into the well bore over the central vertical axis of the bore hole, so that contact between the flexible tubing and the sides or upper lip regions of the well casing is largely avoided.